Spinning apparatus of a centrifugal spinning machine

ABSTRACT

In the spinning unit of a centrifugal spinning machine the yarn conduct (4, 5) mounted between the revolving tube (2) and the yarn spreader (8) is designed so as to open on the side of the rewinding unit consisting of a winding drum (17) and a cartridge holder (18). The yarn conduct opens without displacement of the yarn (28) from its longitudinal axis. This allows to reduce the friction of the yarn (28) against the wall of the yarn conduct (4, 5) during the spinning process and to reduce the friction of the yarn (28) against the wall and the upper end of the spreader (8) during the rewinding process, as well as to bring the rewinding unit closer to the spinning unit.

FIELD OF THE INVENTION

The invention relates to the textile industries or, more specifically,to centrifugal spinning machines, and can be used for the production ofyarns from any type of fibre.

DESCRIPTION OF THE PRIOR ART

There is known a centrifugal spinning machine (M. I. Kulagin. Novyyesposoby pryadeniya sherstyanykh i khimicheskikh volokok (Russ.--NewMethods for Spinning Wool and Man-Made Fibres), Moscow, LegkayaIndustriya (Publishers), 1974, pp. 28-30), wherein each spinning unitcontains a drawing mechanism, a yarn spreader, and a centrifuge. Forspun yarn removal from the centrifuge, special bobbins (spools) areintroduced thereinto, with immobile pirns (cores, tubes) placed over thebobbins. The yarn is thrown over the top end of an immobile pirn to berewound over it by dint of the centrifuge's rotation, with bobbin andpirn withdrawn from the centrifuge thereafter.

One disadvantage of this machine is low output, due to a large number ofmanual operations associated with its use, such as spinning-in, movingbobbins in and out while rewinding, as well as operations associatedwith elimination of yarn breakage aftereffects.

Another disadvantage of this machine is that there is always a risk ofyarn entanglement, while the yarn is rewound from the centrifugerotating at a high speed, because of several/turns leading at a timefrom the centrifuge on to the pirn.

Another prior-art centrifugal spinning machine (M. I. Kulagin. Novyyesposoby pryadeniya sherstayanykh i khimicheskikh volokon (Russ.--NewMethods for Spinning Wool and Man-Made Fibres), Moscow, LegkayaIndustriya (Publishers), 1974, pp. 30-33) has a spinning unit comprisinga pneumatic scroll tube mounted under the drawing mechanism and enablingautomation of the spinning-in operation. However the second of theafore-mentioned disadvantages is likewise inherent in this othermachine, inasmuch as yarn removal from the centrifuge likewise involvesthe use of immobile pirns to be introduced inside the centrifuges.

Also known in the art is a centrifugal spinning machine (SU, A,1,666,587) consisting of several spinning units, each comprising thefollowing elements arranged vertically down the yarn flow path: adrawing mechanism, a scroll tube, a yarn sensor, a cylindrical yarnconductor composed of two vertically spaced sections, with a clampingelement in between, and a centrifuge complete with a yarn spreaderinstalled so as to be capable of moving vertically inside the centrifugebowl which has its open end facing upwards. The machine also containsyarn rewind devices to remove yarn from the centrifuges of the spinningunits and means to thread yarn into the rewind devices, with the numberof both rewind devices and yarn thread-in means being equal to that ofthe spinning units.

The yarn rewind assembly consists of a winding drum and a pirn holdermounted on a lever capable of rotating until the surface of the pirnplaced in the pirn holder is in contact with that of the winding drum.The means to thread yarn into the rewind assembly has the form of twoeye rings mounted one above the other between the clamping element andthe lower section of the yarn conducting cylinder in line with thelatter and roughly at the rewind assembly level. Each of the eye ringsis linked with a lever of its own, and as this is turned the respectiveeye ring is removed from the yarn conductor zone toward the rewindassembly.

While spinning is in progress, the eye rings are in the position alignedwith the yarn conducting cylinder, the yarn mowing vertically throughthe yarn conductor and eye rings from the automatic spinning-in deviceto the centrifuge. When the spun yarn is unloaded from the centrifuge,the clamping element holds the yarn while the eye ring levers are turnedto displace the eye rings in a manner such that the yarn entrainedtherewith should be drawn in between the drum and pirn and wound overthe latter.

Compared to the previously discussed counterpart, this machine affordsautomation of not only the yarn spinning-in operation, but also of spunyarn discharge.

A disadvantage inherent in the machine according to SU, A, 1,666,587lies in the fact that as the yarn formed in the spinning process movesinside the closed yarn conducting cylinder sections it balloons whilebeing rotated, contacting the conductor walls. This delays twistpropagation along the yarn along its path between the centrifuge and thedrawing mechanism, resulting in increased probability of yarnbreakage--the yarn being low in strength--within the twist triangle, inthe spinning process.

Besides, it is not all impossible for low-strength yarn breakage tooccur also in the process of yarn being unloaded from the centrifuge tothe rewind assembly. This is due to the fact that at the outlet from thespreader and while passing through the lower eye ring shifted off theyarn conductor axis the yarn being rewound from the centrifuge is bentat an angle close to the right angle. With such bends, there isincreased friction of the yarn against the spreader wall and end face,and this may cause the insufficiently strong yarn to break.

Finally, the rewind assembly in each spinning place of the machine underdiscussion is located, of necessity, rather far from the respectivespinning unit, thus leading to increased machine width. This is due tothe requirement that, for achieving stable yarn spreading over the pirn,the distance between the surface of the winding drum and the upper endof the lower yarn conductor, whence the yarn is fed to the drum, shouldbe 4 to 5 times greater than the spreading width.

DISCLOSURE OF THE INVENTION

The invention is based upon the objective of providing a centrifugalspinning machine, wherein the cylindrical yarn conductor in the spinningunit would be so designed as to reduce the probability of yarn breakagesboth in the spinning and rewinding processes and wherein it would bepossible to place the rewind assembly closer to the spinning unit tothereby reduce the overall dimensions of the machine without impairingthe stability of yarn spreading over the pirn.

The objective as stated above is achieved by providing that in acentrifugal spinning machine containing several spinning units invertical arrangement, each comprising a drawing mechanism, a scrolltube, a cylindrical yarn conductor, and a centrifuge complete with ayarn spreader, as well as rewind assemblies to remove yarn from thecentrifuges and means to thread yarn from the centrifuges into therewind assemblies, the cylindrical yarn conductor is designed, inaccordance with the invention, as an opening type, at least within thesection from the yarn spreader down to the yarn thread-in means, so thatthe yarn passing over this section becomes exposed on the rewindassembly side while remaining aligned with the yarn conductor cylinder.

The opening section of the yarn conducting cylinder may be designed inthe form of two cylinder halves installed so as to be capable ofrotating about a vertical axle.

The capability of the yarn conductor to open up, without the path of theyarn passing therethrough being altered, will assure, firstly, lowerfriction between the ballooning yarn and the inner surface of the yarnconductor, providing thereby better conditions for twist propagationalong the yarn over the path from the centrifuge to the drawingmechanism, and will enable, secondly, deflection of the yarn to therewind assembly at a small angle to the yarn conductor axis, so that theyarn will bend but slightly at outlet from the spreader and will not besubject, accordingly, to heavy friction against the wall and end face ofthe latter. This will provide for lower yarn breakage probability bothin the spinning process and while rewinding from the centrifuge.Besides, the opening-type of yarn conductor design makes it possible toaccomodate the rewind assembly to the closest possible proximity to thespinning unit without any risk of disturbing effective yarn spreadingover the pirn in the process of yarn unloading from the centrifuge, aswill be shown below in the description of an embodiment of theinvention. The result is reduced width of the spinning machine as awhole.

It is convenient for a suction air duct to be provided under thecentrifuges having their bowls installed open ends down, fitted withholes, in which to install the open ends of the centrifuge bowls.

This will permit of removing from the centrifuges such foreignimpurities as may evolve in the spinning and rewinding processes, aswell as dust and wastes, and will improve the spinning-in conditions.

It is likewise convenient for each spinning unit to contain a means tosupply steam into the centrifuge bowl.

Steam supplied to the centrifuges will favour relaxation of stressessuch as may occur in the yarn when twisted and liable to cause snarlformations and sluff-offs in the rewinding process, these beingpotential causes for yarn breakages.

In the following, the invention will be made more fully apparent througha detailed description of an embodiment thereof, with due references tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of one spinning place in acentrifugal spinning machine according to the invention;

FIG. 2 is section II--II of FIG. 1 at the spinning-in stage;

FIG. 3 is the same as FIG. 2 in the spinning process; and

FIG. 4 is the same as FIG. 2 with yarn being threaded into the rewindassembly.

BEST MODE TO CARRY OUT THE INVENTION

The centrifugal spinning machine consists of a plurality of spinningplaces, each comprising a spinning unit, a yarn rewind assembly toremove yarn from the centrifuge, and a means to thread yarn into therewind assembly. One such spinning place is illustrated in FIG. 1. Thespinning unit comprises, installed one under another, a drawingmechanism 1, a scroll tube 2, e.g. a pneumatic scroll tube, a yarnsensor 3, a cylindrical yarn conductor composed of sections 4 and 5, aclamping element 6 installed in between said sections, and a centrifuge7 complete with a yarn spreader 8 in the form of a hollow cylindermounted in the hollow axle of the centrifuge 7 and provided with avertical displacement capability. Secured to the upper end of thespreader 8 are a second yarn sensor 9 and a second pneumatic scroll tube10 designed to enhance spinning-in reliability. The drive 11 of thecentrifuge 7 is attached to a spindle plate 12 which is part of themachine frame. The drives of the other mobile elements of the machine,specifically those of the clamping element 6, yarn spreader 8, and suchothers as are indicated hereinunder, are omitted from FIG. 1 to avoidcomplicating the drawing.

The clamping element 6 has the form of, e.g., two vertically arrangedplates installed with a clearance to enable passage of yarn in betweenand capable of drawing together to clamp the yarn.

The sensors 3 and 9 may be of photoelectric or capacitive types, such asare widely used on automatic winding machines. The sensor 3 is designedto detect yarn breakages while spinning, the sensor 9 serves the samepurpose while rewinding. The two sensors enable elimination of yarnbreakage aftereffects, and their presence is not essential for thenature of the invention.

In the embodiment under discussion, the bowl of the centrifuge 7 has itsopen end facing downwards, and the spreader 8 enters the bowl throughits bottom. Underneath the bowls of the centrifuge 7 of all the spinningunits in the machine passes a suction air duct 13 with holes 14 fittedtherein to take up the open bowl ends of the centrifuges 7. The bowl ofeach centrifuge 7 is enclosed in a cylindrical guard 15 to reduce thenoise level and to seal the air duct 13 from the environment. The airduct 13 is designed to remove yarn remnants, dust, wastes, etc. from thebowls of the centrifuges 7, enhancing the reliability of spinneroperation and enabling automation of the spinning-in and centrifuge bowlcleaning operations.

The spinning unit has a provision for steam to be supplied into the bowlof the centrifuge 7 for the purpose of relieving such stresses as mayoriginate in the yarn while it is being formed in the spinningprocesses. This purpose is served by a nozzle 16 on the upper part ofthe spreader 8, communicating with a water vapour or steam-air mixturesource (not shown).

The rewind assembly designed to remove yarn from the centrifugecomprised a winding drum 17 and a pirn holder 18, both attached to themachine frame (not shown). The pirn holder 18 is in the form of twolevers 19 (FIGS. 2, 3, and 4) mounting rotary support disks 20 to mountthe pirn 21 and a pressure disk 22 to hold the yarn to the end face ofthe adjacent support disk 20 when the yarn is lead on to the pirn 21.For drive, the pressure disk 22 uses, e.g., an electromagnet 23 securedto one of the levers 19. The levers 19 are mounted on a horizontal axle24 so as to be capable of rotating until the pirn 21 makes contact withthe drum 17, as shown in FIG. 1. Rewind units of this type are widelyused in various kind of spinning and winding equipment.

The means used for threading in yarn into the rewind assembly isdesigned in this embodiment of the invention as a lever 25 fitted with ahook-shaped grip 26. The lever 25 is mounted on a vertical axle 27 in amanner such that its rotation causes the grip 26 to cross thelongitudinal axis of the yarn conductor 4 and 5 (FIG. 1), along whichaxis passes the yarn 28 through the conductor. Other means may also beused to thread yarn into the rewind assembly, thus a nozzle blowing ajet of air on to the pirn 21, etc.

According to the invention, the yarn conductor 4 and 5 is designed inthe form of two half-cylinders 29 (FIGS. 2, 3, and 4) mounted in anarticulated manner on a vertical axle 30, with the parting plane of theyarn cylinder (the jointing plane of the cylinder halves 29) beingnormal to the axis of the winding drum 17. Owing to the split-typeconstruction of the yarn conductor, the rewind assembly composed of thewinding drum 17 and the pirn holder 18 is arranged in the immediateproximity to the axis of the cylindrical yarn conductor 4 and 5, henceto the spinning unit, yet, at the same time, at a sufficient distance,as may be seen from FIG. 1, from the upper end of the spreader, such asis necessary to assure effective yarn spreading over the pirn 21 whenyarn is rewound from the centrifuge 7. It is obvious that the yarnconductor need not be made opening over its entire length, as shown inFIG. 1, only over the section 5 between the spreader 8 and the lever 25,but in this case twist propagation conditions during spinning would besomewhat impaired due to the yarn being in frictional contact with theinner surface of the upper yarn conductor section 4.

It is likewise obvious that the yarn conductor may be split in thehorizontal plane rather than along the generating line of the cylinder,i.e. in the vertical plane, thus it may consist of two or moretelescopically arranged cylinders. Of importance is the fact that, withthe yarn conductor opening up, the yarn 28 passing therethrough becomesexposed on the side of the winding drum 17 and the pirn 21, withoutdeviating from the vertical position.

The machine operates as follows. Prior to start up, the pirn holder 18in each spinning place is drawn away from the drum 17, and a pirn 21 isinstalled in the pirn holder 18. This done, the pirn holder is set inthe operating position, with the pirn 21 held pressed against the drum17. Roving 31 is fed into the drawing mechanism 1. The drive 11 of thecentrifuge 7 is started up and allowed to run up to operating speed. (Itis convenient for the centrifuge drives of the spinning units to bestarted up in succession, shifted in time, so that removal of aspun-yarn package from any of the centrifuges would not necessitatestopping the others.). The operation of a spinning unit begins with thecylinder halves 29 being brought together to form a closed yarnconducting cylinder, as shown in FIG. 2, the plates of the clampingelement 6 (FIG. 1) being set apart, and the spreader 8 set in theuppermost position. The roving 31 starts feeding into the drawingmechanism 1, forming a strand stretched roving at outlet therefrom. Airis supplied into the pneumatic scroll tubes 2 and 10, causing a rotatingair stream oriented to flow in the downward direction through the yarnconductor 4 and 5.

A fan (not shown) is started up to produce suction in the air duct 13,with the result that the air flow through the spreader 8 is additionallyincreased. Water vapour or humidified air is supplied when necessaryinto the nozzle 16 of the spreader 8. The rotating air stream entrainsthe strand to twist it and feed the yarn 28, formed, along the yarnconductor 4 and 5, through the spreader 8, and into the centrifuge 7. Inthe centrifuge 7, the yarn end is thrown against the bowl wall and heldthereto centrifugally, following which the yarn gets twisted on accountof its being rotated with the centrifuge 7. When the sensors 3 and 9detect the presence of yarn in the yarn conductor 4 and 5, the airsupply to the pneumatic scroll tubes 2 and 10 is discontinued, and thecylinder halves 29 of the yarn conductor rotate over the axle 30 to drawapart and occupy the position as shown in FIG. 3. Actually, the sections4 and 5 of the yarn conductor cease to be cylindrical in form, and theyarn 28 is enabled in these sections to freely balloon without touchingthe walls of the cylinder halves 29, owing to which opportunity thetwist imparted by the centrifuge 7 (FIG. 1) is more freely propagatedalong the yarn upwards, until the twist triangle is reached. In themeanwhile the spreader 8 is gradually displaced downwards, providing foryarn to be spread over the inner bowl wall of the centrifuge 7, based ona specified system.

When the spreader 8 reaches its lowermost position and the bowl of thecentrifuge 7 is filled with a layer of yarn, the spun yarn is unloadedfrom the centrifuge 7, winding over the pirn 21. The procedure is asfollows.

The plates of the clamping element 6 are brought together to hold theyarn 28 passing therebetween while the supply of roving 31 into thedrawing mechanism 1 is discontinued. The lever 25 of the thread-in meansis rotated to the position indicated in FIG. 4, its hook 26 gripping theyarn 28 and taking it away to the zone between the support disk 20 andthe pressure disk 22. The electromagnet 23 is switched in at this point,its mobile core bearing upon the disk 22 to press it against the disk20, clamping the yarn 28 between them. The winding drum 17 is started upto impart rotation to the pirn 21, the yarn 28 being entrained inbetween drum and pirn and wound over the latter while being suppliedfrom the centrifuge 7 (FIG. 1) continuing in uninterrupted rotation. Theyarn 28 breaks at the point where it is locked by the clamping element6, its end being likewise wound upon the pirn. While rewinding is inprogress, the spreader 8 travels upwards, thereby assuring constantrewinding conditions up till the rewinding process is complete.

Owing to the rewind assembly being located at a minimal distance fromthe yarn conductor 4 and 5, the yarn 28 is bent but slightly, as shownby dashed line in FIG. 1, when it leaves the spreader 8 and proceeds tothe winding drum 17. The friction of the yarn against the wall and topend of the spreader 8 is therefore minimized, reducing the probabilityof yarn breakages due to rewinding.

In the spinning and rewinding processes, water vapour is supplied fromthe nozzle 16 to heat and humidify the yarn and, as a result, reduce theelastic stresses and degree of electrification therein, therebyimproving yarn processing conditions at the subsequent process stages.

The sensor 9 serves to detect completion of the rewinding process. Thenthe spreader 8 returns to its initial position (at top), the cylinderhalves 29 (FIG. 2) are brought together to form a closed yarn conductingcylinder, and the cycle is resumed.

Synchronization of the drives of the mobile elements comprised in themachine is by a control system (not shown) operating on a specifiedprogram.

In the event of yarn breakage, there are two alternatives foreliminating the after effects. Where the spinning unit comprises aclamping element 6 operable by a signal from the sensor 3, the yarn endformed as a result of breakage is clamped by the element 6, the lever 25supplying yarn to the pirn 21 which serves to take up the yarn rewoundfrom the centrifuge 7. In case the clamping element 6 is not availableor fails to operate for some reason or other, the broken yarn end willbe thrown into the bowl of the centrifuge 7. In such a situation,suffice it to stop the centrifuge 7 for several seconds. No centrifugalforces, gravity, and the air sucked in from top will clean the bowl ofthe centrifuge of what yarn, dust, and fluff may be present thereinwhile the suction air duct 13 will serve to remove these to the wastes,after which the spinning process may be resumed in the manneressentially as described above.

INDUSTRIAL APPLICABILITY

The invention can be used for spinning operations in the textileindustries. The invention can be utilized to best advantage for spinninglow linear strength yarns.

We claim:
 1. A centrifugal spinning machine for making a yarn from afibrous product, having a plurality of spinning units in a verticalarrangement, each spinning unit comprising:a drawing mechanism forforming a strand stretched roving from said fibrous product; a scrolltube below said drawing mechanism for twisting said strand stretchedroving coming from said drawing mechanism to a yarn in the beginning ofa spinning cycle; a vertically positioned cylindrical yarn conductorbelow said scroll tube for directing said yarn coming from said scrolltube; a centrifuge below said yarn conductor for twisting said yarncoming from said yarn conductor during said spinning cycle, saidcentrifuge being provided with a yarn spreader for laying the yarn insaid centrifuge; and said machine further comprising:a rewind assemblypositioned at one side of each of said yarn conductors for rewindingsaid yarn laid in said centrifuge, after the end of a spinning cycle;and a threading means for threading the yarn into said rewind assembly,said threading means being positioned at said one side of said yarnconductor so that at least a portion of said yarn conductor extendsbelow said threading means, said yarn conductor including at least twoparts at least one of which is movable with respect to the other to aposition at which said yarn conductor opens exposing the yarn to saidthreading means at least along said yarn conductor portion extendingbelow said threading means.
 2. A centrifugal spinning machine accordingto claim 1, wherein said yarn conductor includes two halves eachpivotably mounted to rotate about a vertical axle in a directionopposite to the direction of rotation of the other half.
 3. Acentrifugal spinning machine according to claim 1, wherein each of saidspinning units comprises a suction air duct having a hole, saidcentrifuge being provided with a bowl having an open end and positionedwith said open end down in said hole of the suction air duct.
 4. Acentrifugal spinning machine according to claim 3, wherein each of saidspinning units comprises means for supplying steam into said yarnspreader.
 5. A centrifugal spinning machine for making a yarn from afibrous product, having a plurality of spinning units in a verticalarrangement, each spinning unit comprising:a drawing mechanism forforming a strand stretched roving from said fibrous product; a scrolltube below said drawing mechanism for twisting said strand stretchedroving coming from said drawing mechanism to a yarn in the beginning ofa spinning cycle; a vertically positioned cylindrical yarn conductorbelow said scroll tube for directing said yarn coming from said scrolltube; a centrifuge below said yarn conductor for twisting said yarncoming from said yarn conductor during said spinning cycle, saidcentrifuge being provided with a yarn spreader for laying the yarn insaid centrifuge; said machine further comprising:a rewind assemblypositioned at one side of each of said yarn conductors for rewindingsaid yarn laid in said centrifuge, after the end of a spinning cycle; athreading means for threading the yarn into said rewind assembly, saidthreading means being positioned at said one side of said yarn conductorso that at least a portion of said yarn conductor extends below saidthreading means, said yarn conductor including at least two parts atleast one of which is movable with respect to the other to a position atwhich said yarn conductor opens exposing the yarn to said threadingmeans at least along said yarn conductor portion extending below saidthreading means; and wherein each of said yarn conductor includes twohalves each pivotably mounted to rotate about a vertical axle in adirection opposite to the direction of rotation of the other half.